package org.conan.myhadoop.mr;

import java.io.IOException;
import java.util.Iterator;
import java.util.StringTokenizer;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;
import org.conan.myhadoop.hdfs.HdfsUtil;


public class WordCount {

    public static class WordCountMapper extends MapReduceBase implements Mapper<Object, Text, Text, IntWritable> {
        private final static IntWritable one = new IntWritable(1);
        private Text word = new Text();

        @Override
        public void map(Object key, Text value, OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException {
//        	System.out.println("-----------join map-----------");
            StringTokenizer itr = new StringTokenizer(value.toString());
            while (itr.hasMoreTokens()) {
                word.set(itr.nextToken());
                output.collect(word, one);
            }

        }
    }

    public static class WordCountReducer extends MapReduceBase implements Reducer<Text, IntWritable, Text, IntWritable> {
        private IntWritable result = new IntWritable();

        @Override
        public void reduce(Text key, Iterator<IntWritable> values, OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException {
            int sum = 0;
            while (values.hasNext()) {
                sum += values.next().get();
            }
            result.set(sum);
            output.collect(key, result);
        }
    }
    
    
    public static void main(String[] args) throws Exception {
    	
    	String input = "hdfs://172.16.2.80:9000/input/wordcount1";
    	String output = "hdfs://172.16.2.80:9000/output/wordcount2";
    	HdfsUtil hdfsUtil = new HdfsUtil();
    	hdfsUtil.upload("C:/Users/A/Desktop/i-wordcount.txt", input);
    	
    	long startTime = System.currentTimeMillis();

        JobConf conf = new JobConf(WordCount.class);
        conf.setJobName("WordCount");
        conf.addResource("classpath:/hadoop/core-site.xml");
        conf.addResource("classpath:/hadoop/hdfs-site.xml");
        conf.addResource("classpath:/hadoop/mapred-site.xml");

        conf.setOutputKeyClass(Text.class); 
         conf.setOutputValueClass(IntWritable.class);

        conf.setMapperClass(WordCountMapper.class);
        conf.setCombinerClass(WordCountReducer.class);
        conf.setReducerClass(WordCountReducer.class);

        conf.setInputFormat(TextInputFormat.class);
        conf.setOutputFormat(TextOutputFormat.class);

        FileInputFormat.setInputPaths(conf, new Path(input));
        FileOutputFormat.setOutputPath(conf, new Path(output));

        try{
        	JobClient.runJob(conf);
        }catch(Exception e){
        	e.printStackTrace();
        }
        hdfsUtil.cat(output + "/part-00000");
        hdfsUtil.rmr(output);
        long endTime = System.currentTimeMillis();
        System.out.println("totle ansly timt:" + (endTime - startTime)/1000 + "s");
        System.exit(0);
    }

}
